[thirdparty/systemd.git] / man / systemd-gpt-auto-generator.xml

<?xml version="1.0"?>
<!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
  SPDX-License-Identifier: LGPL-2.1+

  This file is part of systemd.

  Copyright 2013 Lennart Poettering
-->
<refentry id="systemd-gpt-auto-generator">

  <refentryinfo>
    <title>systemd-gpt-auto-generator</title>
    <productname>systemd</productname>

    <authorgroup>
      <author>
        <contrib>Developer</contrib>
        <firstname>Lennart</firstname>
        <surname>Poettering</surname>
        <email>lennart@poettering.net</email>
      </author>
    </authorgroup>
  </refentryinfo>

  <refmeta>
    <refentrytitle>systemd-gpt-auto-generator</refentrytitle>
    <manvolnum>8</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>systemd-gpt-auto-generator</refname>
    <refpurpose>Generator for automatically discovering
    and mounting root, <filename>/home</filename> and
    <filename>/srv</filename> partitions, as well as
    discovering and enabling swap partitions, based on GPT
    partition type GUIDs.</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <para><filename>/usr/lib/systemd/system-generators/systemd-gpt-auto-generator</filename></para>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para><filename>systemd-gpt-auto-generator</filename> is a unit
    generator that automatically discovers root,
    <filename>/home</filename>, <filename>/srv</filename> and swap
    partitions and creates mount and swap units for them, based on the
    partition type GUIDs of GUID partition tables (GPT),
    see <ulink url="http://www.uefi.org/specifications">UEFI Specification</ulink>, chapter 5.
    It implements the <ulink
    url="https://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/">Discoverable
    Partitions Specification</ulink>. Note that this generator has no
    effect on non-GPT systems, or where the directories under the
    mount points are already non-empty. Also, on systems where the
    units are explicitly configured (for example, listed in
    <citerefentry
    project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>),
    the units this generator creates are overridden, but additional
    implicit dependencies might be created.</para>

    <para>This generator will only look for root partitions on the
    same physical disk the EFI System Partition (ESP) is located on.
    It will only look for the other partitions on the same physical
    disk the root file system is located on. These partitions will not
    be searched for on systems where the root file system is distributed
    on multiple disks, for example via btrfs RAID.</para>

    <para><filename>systemd-gpt-auto-generator</filename> is useful
    for centralizing file system configuration in the partition table
    and making configuration in <filename>/etc/fstab</filename> unnecessary.
    </para>

    <para>This generator looks for the partitions based on their
    partition type GUID. The following partition type GUIDs are
    identified:</para>

    <table>
      <title>Partition Type GUIDs</title>
      <tgroup cols='3' align='left' colsep='1' rowsep='1'>
        <colspec colname="guid" />
        <colspec colname="name" />
        <colspec colname="explanation" />
        <thead>
          <row>
            <entry>Partition Type GUID</entry>
            <entry>Name</entry>
            <entry>Explanation</entry>
          </row>
        </thead>
        <tbody>
          <row>
            <entry>44479540-f297-41b2-9af7-d131d5f0458a</entry>
            <entry><filename>Root Partition (x86)</filename></entry>
            <entry>On 32-bit x86 systems, the first x86 root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
          </row>
          <row>
            <entry>4f68bce3-e8cd-4db1-96e7-fbcaf984b709</entry>
            <entry><filename>Root Partition (x86-64)</filename></entry>
            <entry>On 64-bit x86 systems, the first x86-64 root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
          </row>
          <row>
            <entry>69dad710-2ce4-4e3c-b16c-21a1d49abed3</entry>
            <entry><filename>Root Partition (32-bit ARM)</filename></entry>
            <entry>On 32-bit ARM systems, the first ARM root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
          </row>
          <row>
            <entry>b921b045-1df0-41c3-af44-4c6f280d3fae</entry>
            <entry><filename>Root Partition (64-bit ARM)</filename></entry>
            <entry>On 64-bit ARM systems, the first ARM root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
          </row>
          <row>
            <entry>993d8d3d-f80e-4225-855a-9daf8ed7ea97</entry>
            <entry><filename>Root Partition (Itanium/IA-64)</filename></entry>
            <entry>On Itanium systems, the first Itanium root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
          </row>
          <row>
            <entry>933ac7e1-2eb4-4f13-b844-0e14e2aef915</entry>
            <entry>Home Partition</entry>
            <entry>The first home partition on the disk the root partition is located on is mounted to <filename>/home</filename>.</entry>
          </row>
          <row>
            <entry>3b8f8425-20e0-4f3b-907f-1a25a76f98e8</entry>
            <entry>Server Data Partition</entry>
            <entry>The first server data partition on the disk the root partition is located on is mounted to <filename>/srv</filename>.</entry>
          </row>
          <row>
            <entry>0657fd6d-a4ab-43c4-84e5-0933c84b4f4f</entry>
            <entry>Swap</entry>
            <entry>All swap partitions located on the disk the root partition is located on are enabled.</entry>
          </row>
          <row>
            <entry>c12a7328-f81f-11d2-ba4b-00a0c93ec93b</entry>
            <entry>EFI System Partition (ESP)</entry>
            <entry>The first ESP located on the disk the root partition is located on is mounted to <filename>/boot</filename> or <filename>/efi</filename>, see below.</entry>
          </row>
        </tbody>
      </tgroup>
    </table>

    <para>This generator understands the following attribute flags for partitions:</para>

    <table>
      <title>Partition Attributes</title>
      <tgroup cols='4' align='left' colsep='1' rowsep='1'>
        <colspec colname="attribute" />
        <colspec colname="value" />
        <colspec colname="where" />
        <colspec colname="explanation" />
        <thead>
          <row>
            <entry>Name</entry>
            <entry>Value</entry>
            <entry>Applicable to</entry>
            <entry>Explanation</entry>
          </row>
        </thead>
        <tbody>
          <row>
            <entry><constant>GPT_FLAG_READ_ONLY</constant></entry>
            <entry>0x1000000000000000</entry>
            <entry><filename>/</filename>, <filename>/srv</filename>, <filename>/home</filename></entry>
            <entry>Partition is mounted read-only</entry>
          </row>

          <row>
            <entry><constant>GPT_FLAG_NO_AUTO</constant></entry>
            <entry>0x8000000000000000</entry>
            <entry><filename>/</filename>, <filename>/srv</filename>, <filename>/home</filename></entry>
            <entry>Partition is not mounted automatically</entry>
          </row>

          <row>
            <entry><constant>GPT_FLAG_NO_BLOCK_IO_PROTOCOL</constant></entry>
            <entry>0x0000000000000002</entry>
            <entry>ESP</entry>
            <entry>Partition is not mounted automatically</entry>
          </row>
        </tbody>
      </tgroup>
    </table>

    <para>The <filename>/home</filename> and <filename>/srv</filename>
    partitions may be encrypted in LUKS format. In this case, a device
    mapper device is set up under the names
    <filename>/dev/mapper/home</filename> and
    <filename>/dev/mapper/srv</filename>. Note that this might create
    conflicts if the same partition is listed in
    <filename>/etc/crypttab</filename> with a different device mapper
    device name.</para>

    <para>Mount and automount units for the EFI System Partition (ESP) are generated on EFI systems. The ESP is mounted
    to <filename>/boot</filename>, unless a mount point directory <filename>/efi</filename> exists, in which case it is
    mounted there. Since this generator creates an automount unit, the mount will only be activated on-demand, when
    accessed. On systems where <filename>/boot</filename> (or <filename>/efi</filename> if it exists) is an explicitly
    configured mount (for example, listed in <citerefentry
    project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>) or where the
    <filename>/boot</filename> (or <filename>/efi</filename>) mount point is non-empty, no mount units are
    generated.</para>

    <para>When using this generator in conjunction with btrfs file
    systems, make sure to set the correct default subvolumes on them,
    using <command>btrfs subvolume set-default</command>.</para>

    <para><filename>systemd-gpt-auto-generator</filename> implements
    <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para>
      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
      <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
      <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
      <citerefentry project='man-pages'><refentrytitle>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
    </para>
  </refsect1>

</refentry>
Commit	Line	Data
d67ca9ab LP	1	<?xml version="1.0"?>
d67ca9ab LP	2	<!---nxml--->
12b42c76	3	<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
d67ca9ab	4	<!--
572eb058 ZJS	5	SPDX-License-Identifier: LGPL-2.1+
572eb058 ZJS	6
d67ca9ab LP	7	This file is part of systemd.
	8
	9	Copyright 2013 Lennart Poettering
d67ca9ab LP	10	-->
	11	<refentry id="systemd-gpt-auto-generator">
	12
798d3a52 ZJS	13	<refentryinfo>
	14	<title>systemd-gpt-auto-generator</title>
	15	<productname>systemd</productname>
	16
	17	<authorgroup>
	18	<author>
	19	<contrib>Developer</contrib>
	20	<firstname>Lennart</firstname>
	21	<surname>Poettering</surname>
	22	<email>lennart@poettering.net</email>
	23	</author>
	24	</authorgroup>
	25	</refentryinfo>
	26
	27	<refmeta>
	28	<refentrytitle>systemd-gpt-auto-generator</refentrytitle>
	29	<manvolnum>8</manvolnum>
	30	</refmeta>
	31
	32	<refnamediv>
	33	<refname>systemd-gpt-auto-generator</refname>
	34	<refpurpose>Generator for automatically discovering
	35	and mounting root, <filename>/home</filename> and
	36	<filename>/srv</filename> partitions, as well as
	37	discovering and enabling swap partitions, based on GPT
	38	partition type GUIDs.</refpurpose>
	39	</refnamediv>
	40
	41	<refsynopsisdiv>
12b42c76	42	<para><filename>/usr/lib/systemd/system-generators/systemd-gpt-auto-generator</filename></para>
798d3a52 ZJS	43	</refsynopsisdiv>
	44
	45	<refsect1>
	46	<title>Description</title>
	47
	48	<para><filename>systemd-gpt-auto-generator</filename> is a unit
	49	generator that automatically discovers root,
	50	<filename>/home</filename>, <filename>/srv</filename> and swap
	51	partitions and creates mount and swap units for them, based on the
8d5a4f27 ZJS	52	partition type GUIDs of GUID partition tables (GPT),
	53	see <ulink url="http://www.uefi.org/specifications">UEFI Specification</ulink>, chapter 5.
	54	It implements the <ulink
28a0ad81	55	url="https://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/">Discoverable
798d3a52	56	Partitions Specification</ulink>. Note that this generator has no
c6355b31 LP	57	effect on non-GPT systems, or where the directories under the
	58	mount points are already non-empty. Also, on systems where the
	59	units are explicitly configured (for example, listed in
	60	<citerefentry
	61	project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>),
dc61b7e4	62	the units this generator creates are overridden, but additional
45f09f93	63	implicit dependencies might be created.</para>
798d3a52 ZJS	64
	65	<para>This generator will only look for root partitions on the
	66	same physical disk the EFI System Partition (ESP) is located on.
	67	It will only look for the other partitions on the same physical
	68	disk the root file system is located on. These partitions will not
8d5a4f27	69	be searched for on systems where the root file system is distributed
798d3a52 ZJS	70	on multiple disks, for example via btrfs RAID.</para>
	71
	72	<para><filename>systemd-gpt-auto-generator</filename> is useful
	73	for centralizing file system configuration in the partition table
8d5a4f27 ZJS	74	and making configuration in <filename>/etc/fstab</filename> unnecessary.
8d5a4f27 ZJS	75	</para>
798d3a52 ZJS	76
	77	<para>This generator looks for the partitions based on their
	78	partition type GUID. The following partition type GUIDs are
	79	identified:</para>
	80
	81	<table>
	82	<title>Partition Type GUIDs</title>
	83	<tgroup cols='3' align='left' colsep='1' rowsep='1'>
	84	<colspec colname="guid" />
	85	<colspec colname="name" />
	86	<colspec colname="explanation" />
	87	<thead>
	88	<row>
	89	<entry>Partition Type GUID</entry>
	90	<entry>Name</entry>
	91	<entry>Explanation</entry>
	92	</row>
	93	</thead>
	94	<tbody>
	95	<row>
	96	<entry>44479540-f297-41b2-9af7-d131d5f0458a</entry>
	97	<entry><filename>Root Partition (x86)</filename></entry>
	98	<entry>On 32-bit x86 systems, the first x86 root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
	99	</row>
	100	<row>
	101	<entry>4f68bce3-e8cd-4db1-96e7-fbcaf984b709</entry>
	102	<entry><filename>Root Partition (x86-64)</filename></entry>
	103	<entry>On 64-bit x86 systems, the first x86-64 root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
	104	</row>
	105	<row>
	106	<entry>69dad710-2ce4-4e3c-b16c-21a1d49abed3</entry>
	107	<entry><filename>Root Partition (32-bit ARM)</filename></entry>
	108	<entry>On 32-bit ARM systems, the first ARM root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
	109	</row>
	110	<row>
	111	<entry>b921b045-1df0-41c3-af44-4c6f280d3fae</entry>
	112	<entry><filename>Root Partition (64-bit ARM)</filename></entry>
	113	<entry>On 64-bit ARM systems, the first ARM root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
	114	</row>
b793ddfa LW	115	<row>
	116	<entry>993d8d3d-f80e-4225-855a-9daf8ed7ea97</entry>
	117	<entry><filename>Root Partition (Itanium/IA-64)</filename></entry>
	118	<entry>On Itanium systems, the first Itanium root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
	119	</row>
798d3a52 ZJS	120	<row>
	121	<entry>933ac7e1-2eb4-4f13-b844-0e14e2aef915</entry>
	122	<entry>Home Partition</entry>
	123	<entry>The first home partition on the disk the root partition is located on is mounted to <filename>/home</filename>.</entry>
	124	</row>
	125	<row>
	126	<entry>3b8f8425-20e0-4f3b-907f-1a25a76f98e8</entry>
	127	<entry>Server Data Partition</entry>
	128	<entry>The first server data partition on the disk the root partition is located on is mounted to <filename>/srv</filename>.</entry>
	129	</row>
	130	<row>
	131	<entry>0657fd6d-a4ab-43c4-84e5-0933c84b4f4f</entry>
	132	<entry>Swap</entry>
	133	<entry>All swap partitions located on the disk the root partition is located on are enabled.</entry>
	134	</row>
b52a109a LP	135	<row>
	136	<entry>c12a7328-f81f-11d2-ba4b-00a0c93ec93b</entry>
	137	<entry>EFI System Partition (ESP)</entry>
	138	<entry>The first ESP located on the disk the root partition is located on is mounted to <filename>/boot</filename> or <filename>/efi</filename>, see below.</entry>
	139	</row>
798d3a52 ZJS	140	</tbody>
	141	</tgroup>
	142	</table>
	143
8d5a4f27 ZJS	144	<para>This generator understands the following attribute flags for partitions:</para>
	145
	146	<table>
	147	<title>Partition Attributes</title>
	148	<tgroup cols='4' align='left' colsep='1' rowsep='1'>
	149	<colspec colname="attribute" />
	150	<colspec colname="value" />
	151	<colspec colname="where" />
	152	<colspec colname="explanation" />
	153	<thead>
	154	<row>
	155	<entry>Name</entry>
	156	<entry>Value</entry>
	157	<entry>Applicable to</entry>
	158	<entry>Explanation</entry>
	159	</row>
	160	</thead>
	161	<tbody>
	162	<row>
	163	<entry><constant>GPT_FLAG_READ_ONLY</constant></entry>
	164	<entry>0x1000000000000000</entry>
	165	<entry><filename>/</filename>, <filename>/srv</filename>, <filename>/home</filename></entry>
	166	<entry>Partition is mounted read-only</entry>
	167	</row>
	168
	169	<row>
	170	<entry><constant>GPT_FLAG_NO_AUTO</constant></entry>
	171	<entry>0x8000000000000000</entry>
	172	<entry><filename>/</filename>, <filename>/srv</filename>, <filename>/home</filename></entry>
	173	<entry>Partition is not mounted automatically</entry>
	174	</row>
	175
	176	<row>
	177	<entry><constant>GPT_FLAG_NO_BLOCK_IO_PROTOCOL</constant></entry>
	178	<entry>0x0000000000000002</entry>
	179	<entry>ESP</entry>
	180	<entry>Partition is not mounted automatically</entry>
	181	</row>
	182	</tbody>
	183	</tgroup>
	184	</table>
	185
798d3a52	186	<para>The <filename>/home</filename> and <filename>/srv</filename>
b938cb90	187	partitions may be encrypted in LUKS format. In this case, a device
798d3a52 ZJS	188	mapper device is set up under the names
	189	<filename>/dev/mapper/home</filename> and
	190	<filename>/dev/mapper/srv</filename>. Note that this might create
	191	conflicts if the same partition is listed in
	192	<filename>/etc/crypttab</filename> with a different device mapper
	193	device name.</para>
	194
b52a109a LP	195	<para>Mount and automount units for the EFI System Partition (ESP) are generated on EFI systems. The ESP is mounted
	196	to <filename>/boot</filename>, unless a mount point directory <filename>/efi</filename> exists, in which case it is
	197	mounted there. Since this generator creates an automount unit, the mount will only be activated on-demand, when
	198	accessed. On systems where <filename>/boot</filename> (or <filename>/efi</filename> if it exists) is an explicitly
	199	configured mount (for example, listed in <citerefentry
	200	project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>) or where the
	201	<filename>/boot</filename> (or <filename>/efi</filename>) mount point is non-empty, no mount units are
	202	generated.</para>
798d3a52 ZJS	203
	204	<para>When using this generator in conjunction with btrfs file
	205	systems, make sure to set the correct default subvolumes on them,
	206	using <command>btrfs subvolume set-default</command>.</para>
	207
	208	<para><filename>systemd-gpt-auto-generator</filename> implements
b1c1a519	209	<citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
798d3a52 ZJS	210	</refsect1>
	211
	212	<refsect1>
	213	<title>See Also</title>
	214	<para>
	215	<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
	216	<citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	217	<citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	218	<citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
798d3a52	219	<citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
3ba3a79d ZJS	220	<citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
	221	<citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	222	<citerefentry project='man-pages'><refentrytitle>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
798d3a52 ZJS	223	</para>
798d3a52 ZJS	224	</refsect1>
d67ca9ab LP	225
d67ca9ab LP	226	</refentry>